[1]} tackled the study of stability of a fluid comprised between two concentric rotating cylinders at high \(R\) . It was generalized for any value of \(R\)  by [2]} who showed that particular independent solutions were given by:
\(v_1(r,\varphi ,z) = f(r)*e^{i(n\varphi + kz - \omega t)}\) 
